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We present a calculation of the neutrino-nucleon scattering cross-section which takes into account the nuclear correlations
in the relativistic random phase approximation (RPA). Our approach is based on a quantum-hadrodynamics model with exchange
of σ, ω, π, ρ and δ mesons. In view of applications to neutrino transport in the final stages of supernova explosion and proto-neutron
star cooling, we study the evolution of the neutrino mean free path as a function of density, proton-neutron asymmetry and
temperature. Special attention was paid to the issues of renormalization of the Dirac sea, residual interactions in the tensor
channel, coupling to the delta-meson and meson mixing. In contrast with the results of other authors, we find that the neutral-current
process is not sensitive to the strength g' of the residual contact interaction. As a consequence, it is found that RPA corrections with respect to the mean-field approximation
amount to only 10% to 15% at high density.
Received: 27 June 2001 / Accepted: 14 January 2002 相似文献
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L. Mornas F. Calvayrac E. Suraud P.-G. Reinhard 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1996,38(1):73-79
We investigate the dynamics of the electron cloud in a metal cluster from the regime of small oscillations up to high excitations in the multi-plasmon regime. Particular attention is paid to the effect of spin modes. Test cases are a spin saturated cluster, Na9 +, and a strongly spin polarized cluster, the spherical isomer of Na6 +. The spectral distributions are dominated by the Mie plasmon resonance and a strong collective spin mode in all cases considered. Nonlinear effects as cross talk between multi-plasmon states or chaotic pattern cannot be observed in the investigated energy range. 相似文献
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